LXR qemu/tests/multiboot/libc.c

   1/*
   2 * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a copy
   5 * of this software and associated documentation files (the "Software"), to deal
   6 * in the Software without restriction, including without limitation the rights
   7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8 * copies of the Software, and to permit persons to whom the Software is
   9 * furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice shall be included in
  12 * all copies or substantial portions of the Software.
  13 *
  14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  17 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20 * THE SOFTWARE.
  21 */
  22
  23#include "libc.h"
  24
  25void* memcpy(void *dest, const void *src, int n)
  26{
  27    char *d = dest;
  28    const char *s = src;
  29
  30    while (n--) {
  31        *d++ = *s++;
  32    }
  33
  34    return dest;
  35}
  36
  37static void print_char(char c)
  38{
  39    outb(0xe9, c);
  40}
  41
  42static void print_str(char *s)
  43{
  44    while (*s) {
  45        print_char(*s++);
  46    }
  47}
  48
  49static void print_num(uint64_t value, int base)
  50{
  51    char digits[] = "0123456789abcdef";
  52    char buf[32] = { 0 };
  53    int i = sizeof(buf) - 2;
  54
  55    do {
  56        buf[i--] = digits[value % base];
  57        value /= base;
  58    } while (value);
  59
  60    print_str(&buf[i + 1]);
  61}
  62
  63void printf(const char *fmt, ...)
  64{
  65    va_list ap;
  66    uint64_t val;
  67    char *str;
  68    int base;
  69    int has_long;
  70    int alt_form;
  71
  72    va_start(ap, fmt);
  73
  74    for (; *fmt; fmt++) {
  75        if (*fmt != '%') {
  76            print_char(*fmt);
  77            continue;
  78        }
  79        fmt++;
  80
  81        if (*fmt == '#') {
  82            fmt++;
  83            alt_form = 1;
  84        } else {
  85            alt_form = 0;
  86        }
  87
  88        if (*fmt == 'l') {
  89            fmt++;
  90            if (*fmt == 'l') {
  91                fmt++;
  92                has_long = 2;
  93            } else {
  94                has_long = 1;
  95            }
  96        } else {
  97            has_long = 0;
  98        }
  99
 100        switch (*fmt) {
 101        case 'x':
 102        case 'p':
 103            base = 16;
 104            goto convert_number;
 105        case 'd':
 106        case 'i':
 107        case 'u':
 108            base = 10;
 109            goto convert_number;
 110        case 'o':
 111            base = 8;
 112            goto convert_number;
 113
 114        convert_number:
 115            switch (has_long) {
 116            case 0:
 117                val = va_arg(ap, unsigned int);
 118                break;
 119            case 1:
 120                val = va_arg(ap, unsigned long);
 121                break;
 122            case 2:
 123                val = va_arg(ap, unsigned long long);
 124                break;
 125            }
 126
 127            if (alt_form && base == 16) {
 128                print_str("0x");
 129            }
 130
 131            print_num(val, base);
 132            break;
 133
 134        case 's':
 135            str = va_arg(ap, char*);
 136            print_str(str);
 137            break;
 138        case '%':
 139            print_char(*fmt);
 140            break;
 141        default:
 142            print_char('%');
 143            print_char(*fmt);
 144            break;
 145        }
 146    }
 147
 148    va_end(ap);
 149}
 150
 151
 152